Greenest cities

Top 10

Portland, Oregon

Named by National Geographic as one of 2010â€™s bike-friendliest cities, Portland, Oregon, holds the top spot for more than one top 10 green list, including TreeHugger.comâ€™s â€œfive of the greenest cities in the world to visit." Portland is considered green for more reasons than its 37,000 acres of urban parks and 166 miles of trails. The city also boasts one of the country's highest recycling rates (at least 52 percent); the highest percentage of bicycle commuters (3.5 percent) and the most LEED-certified buildings per capita in the US.